Cardiac rhabdomyomas in tuberous sclerosis - prenatal and neonatal findings


This is a case of fetal cardiac rhabdomyomas leading to the early diagnosis of tuberous sclerosis.
At birth, clinical examination revealed a few achromic macules. Genetic investigations revealed a familial condition.

Multiples prenatal cardiac tumors have almost no differential: rhabdomyomas, with typical bright hyperechogenicity. Spontaneous involution is expected after birth. In some cases, they may be temporarily obstructive and hinder cardiac outflow.

In 40-60% of cases in some series, fetal rhabdomyomas predicts tuberous sclerosis. Hence prenatal MR is performed to look for tubers and subependymal nodules. Prenatal tubers display reversed MR signal compared to pediatric and adult tubers in a myelinated brain. 

Tubers and subependymal nodules may appear months or years later, hence, a negative prenatal brain MRI does not rule out tuberous sclerosis. Genetics research for the most common mutation of TSC1 and TSC2 genes do contribute to the prenatal diagnosis for counseling, especially in case of a negative prenatal brain MRI. 

Tuberous sclerosis (OMIM #191100) can be de novo or inherited in a dominant autosomal fashion. However, penetrance and phenotypic expression are variable, and clinical symptoms may be absent in mildly affected individuals. 

Dr F Cuillier and Dr M Balu both significantly contributed to this case.